Precision of statistical estimation

• Width of a confidence interval gives a measure of the
  precision of the statistical estimation

 Estimation of population value can achieve higher
precision by minimizing S.E. , which depends on the
population s.d. and sample size, that is S.E. can be
minimized by maximizing sample size (up to a certain point)

X 1.96S.E.^ X X+1.96S.E.^

Low precision estimation

X X

X 1.96S.E.^ X X+1.96S.E.^

high precision estimation

X X

X

X